From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751251AbWDNOTj (ORCPT ); Fri, 14 Apr 2006 10:19:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751254AbWDNOTj (ORCPT ); Fri, 14 Apr 2006 10:19:39 -0400 Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:491 "EHLO lxorguk.ukuu.org.uk") by vger.kernel.org with ESMTP id S1751251AbWDNOTi (ORCPT ); Fri, 14 Apr 2006 10:19:38 -0400 Subject: Re: Direct writing to the IDE on panic? From: Alan Cox To: Steven Rostedt Cc: LKML In-Reply-To: <1144936547.1336.20.camel@localhost.localdomain> References: <1144936547.1336.20.camel@localhost.localdomain> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Fri, 14 Apr 2006 15:28:34 +0100 Message-Id: <1145024914.17531.21.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Iau, 2006-04-13 at 09:55 -0400, Steven Rostedt wrote: > Hi, > > I was wondering if anyone has done some work to directly write and poll > to the IDE? This is to store data on a panic or oops. So it would need > to bypass pretty much all the normal Linux mechanisms to do low lever > IDE work. I've seen some 2.4 work here. For 2.6 the current focus is kexec of course > Obviously, this would be a slow process, but the system has crashed and > we care more about retrieving information than speed. > > Has this already been done and what issues need to be addressed? The big issue is 'how am I sure the partition data and code I run are valid post crash'. You don't want the risk of dumping to the wrong part of the disk and making a crash into a disaster.